The present invention relates to a manufacturing technology for electronic parts such as semiconductor devices. More particularly, the present invention is concerned with an ion beam processing technology for processing a section of a sample with an ion beam, or for processing a sample so as to separate a micro test piece from the sample or make preparations for the separation.
Manufacture of electronic parts such as semiconductor memories represented by a dynamic random access memory (DRAM), microprocessors, semiconductor devices including a semiconductor laser, and magnetic heads is requested to offer a high yield. This is because a decrease in the yield derived from production of a defective invites degradation of cost-effectiveness. Therefore, it is a critical problem how a defect or a foreign matter causing a defective or an imperfectly processed good is discovered in an early stage and what measures are taken. For example, at a site of manufacturing an electronic part, efforts are made to discover a defective by performing close inspection and to analyze the cause of occurrence of the defect. In an actual electronic part manufacturing process in which wafers are treated, a wafer that is being processed is inspected in order to track down the cause of an abnormality such as a defect in a circuit pattern or a foreign matter, and a countermeasure is discussed.
Normally, a scanning electron microscope (SEM) offering a high resolution is used to observe an abnormality in a sample. In recent years, a complex FIB-SEM machine that uses a focused ion beam (FIB) in combination with the SEM has been employed. In the FIB-SEM machine, the FIB is irradiated in order to form an angular hole in a desired region so that the section can be observed using the SEM.
For example, Japanese Patent Application Laid-Open No. 2002-150990 has proposed an apparatus that forms a rectangular hole near an abnormality in a sample using the FIB, observes the section of the rectangular hole using the SEM, and thus observes or analyzes a defect or a foreign matter.
Moreover, PCT International Publication WO99/05506 has proposed a technology for extracting a micro test piece, which is to be observed using a transmission electron microscope (TEM), from a bulk sample using the FIB and a probe.
Moreover, Japanese Patent Application Laid-Open No. 2000-156393 has proposed a technique of extracting a micro test piece to be inspected from a wafer without breaking the wafer, and returning the wafer, from which the micro test piece is extracted, to a production line. According to the technique, a progress in a machining process is monitored using a monitor, and a wafer is inspected or analyzed.
Moreover, Japanese Patent Application Laid-Open No. 7-320670 has proposed a technology for processing a sample, which is to be observed using the SEM, with an argon ion beam whose beam spot has a diameter of 0.1 μm and which is generated by a helicon wave ion source.